Spherical disc valve assembly

ABSTRACT

A disc valve assembly, particularly useful between flanges, which utilizes a housing unit and a separate valve unit. The housing unit and the valve unit are adapted so that a minimum contact area is established therebetween. The housing unit provides a supporting housing adapted to be supported between the flanges, and includes a first valve stem. The valve unit is sized to be inserted in the housing unit and includes a disc valve member, a seat and a pair of valve stems. One of the stems is journaled in the valve body and is adapted to be interconnected to the first valve stem, and secured to the disc valve member. The other valve stem is connected to the disc valve member and is journaled in the valve body.

s 101 Units States atent 1 51 3,666,234 Scaramucci 1 May 30, 1972 [54]SPIERICAL DISC VALVE ASSEMBLY 3,491,796 1/1970 Scaramucci ..251/315 [72]Inventor: Dom" Sc ed, 3245 South Hattie 3,333,;78 2/1973 Priese....251/315 X Oklahoma City, Okla 73129 6 9/193 Rector... ..251/29l X2,592,062 4/1952 Perry ..251/3l5 X [22] Filed: Aug. 27, 1969 3,081,7913/1963 Wheatley... 137/4542 3,118,465 1/1964 Scaramucci .....137/454.2[211 853338 3,245,653 4/1966 Lavigueur ..25 1/315 x Related U.S.Application Data Primary Examiner-Henry T. Klinksiek [63]Contmuatton-in-part of Ser. No. 763,644, Sept. 30,

1968, Pat. No. 3,531,081 Attorney Dunlap, Laney, l-lessln & Dougherty 52U.S. c1 ..251/151, 134/454.2, 251/298, [57] ABSTRACT 2 251/315 A discvalve assembly, particularly useful between flanges, [51] Int. Cl ..Fl6k51/00, F16k 25/00 which utilizes a housing unit and a separate valveunit, The Field Search 37, 95, 251/143, housing unit and the valve unitare adapted so that a minimum 251/291, 306, 315, 174; contact area isestablished therebetween. The housing unit 137/4542 provides asupporting housing adapted to be supported between the flanges, andincludes a first valve stem. The valve [56] References Cited unit issized to be inserted in the housing unit and includes a disc valvemember a seat and a pair of valve stems. One of the T AT S P TENT UNI EDST E A s stems is journaled in the valve body and is adapted to beinter- StOut et a1 X connected to the first valve stem and ecured to thevalve 2,789,785 4/1957 Woods ..251/ 174 member The other valve stem isconnected to the disc valve 3,083,725 4/1963 Moen ..251/317 X member andisjoumaled in the valve body 3,127,909 4/1964 Alamprese.. ..25l/3l6 X3,208,472 9/1965 Scaramucci ..l37/454.2 11 Claims, 4 Drawing Figures 62V 64 .a a 66 42 /2 ll? I52 24 76 26 76 \Jd 55 I /28 30 74 g 20 28 iiPATENTED HAY 30 I972 SHEET 2 BF 2 M HMH CROSS-REFERENCE TO RELATEDAPPLICATIONS This application is a continuation-in-part of applicantscopending application entitled Valve Assembly With Insertable ValveUnit, Ser. No. 763,644, filed Sept. 30, 1968, now US. Pat. No.3,531,081.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates generally to improvements in valve assemblies utilizing ahousing unit and a separate valve unit, and more particularly, but notby way of limitation, to an improved disc valve assembly utilizing ahousing unit and a separate valve unit.

2. Description of the Prior Art Applicants co-pending application, ValveAssembly with Insertable Valve Unit," Ser. No. 763,644, filed Sept. 30,1968, disclosed a butterfly valve assembly having a separate housingunit and a separate valve unit. In that disclosure the butterfly valvemember was journaled in the valve body using two separate valve stems.The valve unit was insertable in the housing unit, the outer peripheryof the valve body being sized to slidingly fit in the housing. There areapplications, particularly those involving the control of corrosivefluids, or those where the valve is to be used in a corrosiveatmosphere, where it is desirable to maintain the contacting areabetween the valve unit and the housing to a minimum.

SUMMARY OF THE INVENTION The present invention contemplates, in oneaspect thereof, a valve assembly for controlling the flow of fluidbetween a pair of aligned pipe flanges interconnected by a plurality ofcircumferentially spaced bolts. The valve assembly includes a housinghaving opposite end faces, a bore extending therethrough and adapted tobe supported between the flanges by the bolts. A first valve stem havingan upper and a lower end is journaled in the housing. A valve unit issupported in the housing, and includes a valve body which is adapted tobe inserted lengthwise into the housing. The valve body has oppositeends and a bore extending therethrough intersecting the opposite ends.The outer periphery of the valve body is sized to be less than the innerperiphery formed by the bore in the housing. A hollow, substantiallyhemispherically shaped disc valve member, is supported in the bore ofthe valve body for opening and closing the valve assembly. A secondvalve stem is secured to the disc valve member, and has an upper andlower end portion. The second valve stem is journaled in the valve bodyand the upper end portion thereof is adapted to be connected to thefirst valve stem to the disc valve member. A seat is provided to form aseal between the valve body and the disc valve member when the discvalvemember is in the closed position.

An object of the invention is to facilitate the repair of valveassemblies in the field.

Another object of this invention is to provide a disc valve assemblywherein the cost to manufacture and assemble the parts of the valveassembly is reduced to a minimum, and the valve assembly will have along service life.

A further object of the invention is to provide a disc valve assemblywherein the disc valve member is positively located and journaled in thevalve chamber by a pair of valve stems which are removably connected tothe disc valve member.

A still further object of the invention is to provide a disc valveassembly wherein the disc valve member is shaped to provide improvedflow characteristics and may be quickly and easily removed.

Another object of the invention is to provide a valve assembly having aninsertable valve umt, wherein the contact area between the housing unitand the valve unit is reduced to a minimum to facilitate insertion andremoval of the valve unit.

Other objects and advantages of the invention will be evident from thefollowing detailed description when read in conjunction with theaccompanying drawings which illustrate various embodiments of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a valveassembly, shown in the closed position and assembled between twoflanges.

FIG. 2 is a partial sectional view of the valve assembly of FIG. 1,taken substantially along the lines 2-2 of FIG. I, but showing the discvalve member in elevation and in a partially open position.

FIG. 3 is a view similar to FIG. 1, but illustrating a modified valveassembly.

FIG. 4 is a partial sectional view of the valve assembly of FIG. 3,taken substantially along the lines 4-4 of FIG. 3, but showing themodified valve member in elevation and in a partially open position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings indetail, and to FIGS. 1 and 2 in particular, shown therein and designatedby the general reference character 10, is a valve assembly whichbasically comprises a housing unit 12 and a valve unit 14. The valveassembly 10 is disposed generally between a pair of flanges l6 and 18.

Each of the flanges 16 and 18 includes an end face 20 and 22, and athreaded opening 24 and 26, respectively. The threaded openings 24 and26 are axially aligned and sized to receive the threaded ends ofadjacent sections of a conduit (not shown). Each of the flanges 16 and18 also includes a plurality of circumferentially spaced apertures 28extending therethrough.

The housing unit 12 includes a tubular housing 30 having opposite endfaces 32 and 34 and a bore 36 extending therethrough. A counterbore 38is formed in the end 32 of the housing 30, thereby providing an annularwall 40 facing the respective end of the housing 30.

An aperture 42 extends transversely through the housing 30 intersectingthe bore 36. A counterbore 44 is formed in the aperture 42 adjacent thebore 36 of the housing 30, thereby providing a downwardly facing surface46 in the housing 30.

A first valve stem 48 is journaled in the housing 30, and extendsthrough the transversely extending aperture 42. Thus the center line ofthe first valve stem 48 extends at a right angle to the center line ofthe bore 36 in the housing 30. The first valve stem 48 includes a lowerflange portion 50 having a slot 52 therethrough and being shaped to forman upwardly facing surface 54 encircling the first valve stem 48. Thelower portion 50 is sized to slidingly fit in the counterbore 44 of theaperture 42, and in an assembled position, as shown in FIG. 1, the lowerflange portion 50 will extend a distance in the counterbore 44.

An O-ring seal member 56 is disposed in the counterbore 44 generallybetween the downwardly facing surface 46 of the housing 30 and theupwardly facing surface 54 of the lower flange portion 50. In anassembled position, the O-ring seal 56 is compressed between the lowerflange portion 50 and the downwardly facing surface 46, and forms afluid tight seal therebetween. It should be further noted that theengagement of the flange portion 50 of the first valve stem 48 with thesurface of the counterbore 44 in the housing 30 will provide a secondarymetal-to-metal seal in the event the O-ring 56 is partially destroyed byfire. The engagement of the lower flange portion 50 of the first valvestem 48 with the O-ring seal 56 in the counterbore 44 limits the upwardmovement of the first valve stem 48 in the aperture 42.

A handle 58 is connected to the upper end of the first valve stem 48 bya pin 60. The handle 58 includes a flange portion 62 that is engageablewith a pair of stop pins 64 (only one is shown) to limit the rotationalmovement of the handle 58 to approximately The stop pins 64 are disposedin a pair of holes 66 (only one is shown) in the housing 30. As may beobserved in FIGS. 1 and 2, the handle 58, and more particularly theflange portion 62 thereof, will limit the downward movement of the firstvalve stem 48 in the aperture 42.

A pair of flanges 68 extend outwardly from the housing 30, and two boltholes 70 are provided extending therethrough.

The housing unit 12, the valve unit 14 and the flanges 16 and 18 areheld in assembled relationship by a plurality of the assembled position.

The valve unit 14 includes a valve body 76, having opposite ends 78 and80, and having an outer periphery 82 sized to be less in diameter thanthe bore 36 in the housing 30, for reasons which will be made moreapparent hereinafter. The valve body 76 also includes a flange portion84 formed on the outer periphery 82 adjacent the end 78 of the valvebody 76. The flange portion 84 has an end face 86 and an outer periphery88. The end face 86 is coplanar with the end face 78 of the valve body76, and the outer periphery 88 is sized to slidingly fit in thecounterbore 38 of the housing 30.

The length of the valve body 72, as measured from the end 78 axially tothe end 80, is less than the length of the housing 30, as measured fromthe end 32 axially to the end 34. Therefore, when the valve unit 14 isin the assembled position, as shown more clearly in FIG. 1, the valvebody 76 will extend only partially through the bore 36 of the housing30. The flange portion 84 of the valve body 76 is sized with respect tothe counterbore 38 in the housing 30, such that the end faces 78 and 80of the valve body 76 and the flange portion 84, respectively, willextend axially beyond the end face 32 of the housing 30.

A bore 90 extends through the valve body 76 intersecting the end faces78 and 80 thereof. A spherically shaped seating surface 92 is formed ina portion of the bore 90 of the valve body 76. One end of the seatingsurface 92 intersects the end 80 of the valve body 76 and the oppositeend of the seating surface 92 intersects the bore 90 in the valve body76. The spherically shaped seating surface 92 is sized and shaped tomatingly and seatingly engage the exterior surface of the valve member,as will be described below.

An annular groove 94 is formed in the spherically shaped seating surface92, and an O-ring seal member 96 is disposed in the groove 94. TheO-ring 96 is sized to sealingly engage a portion of the exterior surfaceof the valve member about an outer periphery thereof.

Upper and lower apertures 98 and 100, respectively, extend transverselythrough the valve body 76 intersecting the bore 90, or more particularlythe seating surface 92 therein. In a preferred form, as shown in FIGS. 1and 2, the upper and lower apertures 98 and 100 are radially aligned,for reasons which will be made more apparent hereinafter.

A disc valve member 102 is movably disposed in the bore 90 in the valvebody 76. The disc valve member 102 has a hollow, partial hemisphericalshape defining a circular shaped edge 103 in one cross section thereof.The disc valve member 102 has an outer periphery 104 which is formed ona curvature having its center generally at the center of the disc valvemember 102, along the turning axis thereof.

The outer periphery 104 of the disc valve member 102 is sized, and thedisc valve member 102 is disposed in the bore 90 of the valve body 76,such that the outer periphery 104 seatingly and slidingly engages theseating surface 92 formed in the valve body 76. The O-ring seal member96 is sized to sealingly engage a portion of the outer periphery 104,thereby fonning a fluid tight seal therebetween.

The disc valve member 102 has a flat face 106 formed on a portion of theouter periphery 104. The flat portion 106 of the disc valve member 102is sized such that when the disc valve member 102 has been rotated tothe closed position, as shown in FIG. 1, the bore of the valve body 76substantially encompasses the flat portion 106.

As shown more clearly in FIG. 2, an upper flange 109 is formed on theedge 103 at an upper portion of the disc valve member 102. The upperflange 109 extends axially from the edge 103 when the disc valve member102 is in the closed position. A lower flange portion 111 is formed onthe edge 103 at a lower portion of the disc valve member 102 generallyopposite the upper flange 109. The lower flange 111 extends axially fromthe edge 103 when the disc valve member 102 is in the closed position.An upper aperture 110 extends-through the upper flange portion 109, anda lower aperture 112 extends through the lower flange 111. The apertures110 and 112 are aligned and are disposed, such that in the assembledposition, the upper aperture 110 of the disc valve member 102 is alignedwith the upper aperture 98 in the valve body 76 and the lower aperture112 of the disc valve member 102 is aligned with the lower aperture inthe valve body 76.

A second valve stem 114 extends downwardly through the upper aperture 98of the valve body 76, and is journaled therein. A lower portion 1 16 ofthe second valve stem 1 14 extends through the upper aperture of thedisc valve member 102. The second valve stem 1 14 is secured to the discvalve member 102 by a threaded pin 118, which extends through a threadedaperture formed in the upper flange 109 of the disc valve member 102 andinto a threaded recess 124 formed in the lower portion 116 of the secondvalve stem 1 14.

A rectangular end 126 is formed on the upper most end portion of thesecond valve stem 1 14, and is shaped to matingly fit in the slot 52 ofthe first valve stem 48, thereby providing the interconnectiontherebetween.

A third valve stem 128 extends upwardly through the lower aperture 100of the valve body 76, and is journaled therein. An upper portion 130 ofthe third valve stem 128 extends through the lower aperture 112 of thelower flange portion 111. The third valve stem 128 is secured to thedisc valve member 102 by a threaded pin 132, which extends through athreaded aperture 134 formed in the lower flange portion 1 1 1 of thedisc valve member 102 and into a threaded recess 136 formed in the upperportion 130 of the third valve stem 128.

It is apparent from the foregoing that the disc valve member 102 isjournaled in the valve body 76 at upper and lower portions thereof viathe second and third valve stems 114 and 128, respectively, and that thedisc valve member 102 may be rotated from a fully open to a fully closedposition by turning the handle 58 via the interconnection between thefirst valve stem 48 and the second valve stem 1 14.

A seal gasket 138 is disposed between the end face 20 of the flange 16and the end faces 78 and 86 of the valve body 72 and the flange 84,respectively, thereby providing a fluid tight seal therebetween. Asecond seal gasket 140 is disposed between the end face 22 of the flange18 and the end face 34 of the housing 30, thereby providing a fluidtight seal therebetween.

OPERATION OF FIGS. 1 AND 2 The valve unit 14 is assembled as a separateunit, and is adapted to be inserted lengthwise into the bore 36 of thehousing 30 to a position wherein the flange portion 84 of the valve body76 abuts the wall 40 formed by the counterbore 38 in the housing 30. Inthis position, the rectangular portion 126 of the second valve stem 114will be disposed in the slot 52 of the first valve stem 48. Since theouter periphery 82 of the valve body 76 is less in diameter than theperiphery formed by the bore 36 in the housing 30, a chamber 142 will beformed between a portion of the valve body 76 and a portion of thehousing 30 when the housing unit 14 is in an assembled position, asshown in FIGS. 1 and 2. The chamber 142 is sized to provide ample spaceto accommodate the rectangular end 126 of the second valve stem 1 14 andthe lower flange portion 50 of the first valve stem 48.

The flanges 16 and 18 are disposed on opposite ends of the housing unit12 and the valve unit 14. The valve assembly is held in assembledrelationship by the bolts 72, and is secured in this position by thenuts 74, as described before.

The turning movement of the valve handle 58 is transmitted to the discvalve member 102 in a manner described before, so that the disc valvemember 102 may be rotated from an open to a closed position. As shown inFIG. 2, the disc valve member 102 has been rotated to a partially openposition, and as shown therein the outer edge 103 of the disc valvemember 102 will cooperate with a portion of the bore 90 of the valvebody 76 to define the fluid passageway through the valve assembly 10.

When the disc valve member 102 has been rotated to the closed position,as shown in FIG. 1, the O-ring seal member 96 will sealingly engage thedisc valve member 102 and no fluid will flow through the valve assembly10.

It is apparent from the foregoing that the valve assembly 10 provides avalve assembly wherein the valve unit 14 may be quickly and easilyremoved for repair or replacement.

Since the second and third valve stems 114 and 128, respectively, areremovably pinned to the disc valve member 102 by the pins 118 and 132,respectively, it is apparent that the disc valve member 102 may bequickly and easily assembled or disassembled from the valve body 76.This facilitates repair or replacement of the valve stems 114 and 128,the O-ring seal member 96, or the disc valve member 102.

It should also be noted that, since the only contacting area between thevalve body 76 and the housing 30 is between the flange portion 84 of thevalve body 76 and the counterbore 38 of the housing 30, the fact that acertain amount of corrosion may take place therebetween, in actual useof the valve assembly 10, will not greatly affect the ease with whichthe valve unit 14 may be inserted and removed from the housing unit. Itshould also be noted that since a sliding fit is not required betweenthe outer periphery 82 of the valve body 76 and the inner peripheryformed by the bore 34 of the housing 30, the cost of manufacturing thevalve assembly is correspondingly reduced.

The valve assembly described before also provides a valve assemblywherein the valve unit is insertable and removable for repair orreplacement, thereby reducing downtime encountered during field repairof the valve assembly 10.

EMBODIMENT OF FIGS. 3 AND 4 The valve assembly 10a, shown in FIGS. 3 and4, is constructed in the same manner as the valve assembly 10, shown inFIGS. 1 and 2, except as described below.

The housing 30a has a flange portion 150 formed on end 34 thereof. Theflange portion 150 extends radially inwardly and about the periphery ofthe bore 36 of the housing 30a. The end face of the flange portion 150is coplanar with the end face 34 of the housing 30a, and provides anadditional contacting area between the end face 22 of the flange 18 andthe housing 30a. This type of construction may be desirable in someapplications, particularly those involving high pressure.

The valve body 76a does not have a seating surface formed therein, suchas the seating surface 92 in the valve body 76, shown in FIGS. 1 and 2,for reasons to be made apparent below. A counterbore 152 is formed inthe valve body 72a intersecting the end 80 thereof, and an additionalcounterbore 154 is formed in the counterbore 152 intersecting the bore90 in the valve body 76a. The upper and lower apertures 98a and 100a,respectively, are identical to the upper and lower apertures 98 and 100,shown in FIG. 1 and 2, except the upper and lower apertures 98a and 100aintersect the counterbore 152 in the valve body 76a.

An annular seat 156, having a valve member end 158 and a non-valvemember end 160 is disposed in the counter bore 154 of the valve body76a. The seat 156 may be constructed of a metal or an elastomericmaterial. The outer periphery of the seat 156 is sized to slidingly fitin the counterbore 154 of the valve body 76a.

A seating and sealing surface 162 is formed on a portion of the valvemember end 158 of the annular seat 156. The seating and sealing surface162 is sized and positioned in the valve body 76a to sealing engage aportion of the exterior surface of the disc valve member, as will bedescribed below.

The disc valve member 102a is constructed similar to the disc valvemember 102, shown in FIGS. 1 and 2, except the disc valve member 102adoes not have a flat portion formed thereon, but rather is sphericallyshaped over a major portion of the outer periphery 104a thereof.

A raised portion 166 is formed on the outer surface of the upper flangeportion 109a around the upper aperture 110a in the disc valve member102a. The raised portion 166 has an outer end 168 sized and positionedto bearingly contact the adjacent portion of the counterbore 152 in thevalve body 76a when the disc valve member 102a is in the assembledposition. A second raised portion is formed on the outer surface of thelower flange portion 1 1 10 around the lower aperture 1 12a in the discvalve member 102a. The raised portion 170 has an outer end 172 sized andpositioned to bearingly contact the adjacent portion of the counterbore152 in the valve body 76a when the disc valve member 102a is in theassembled position.

The upper portion 1300 of the third valve stem 128a slidingly extendsinto the lower aperture 112a of the lower flange portion 1 1 1a, but isnot secured therein. The third valve stem 128a extends through the loweraperture 100a, and a lower portion 174 thereof is sized to extend beyondthe outer periphery 82 of the valve body 76a, and in an assembledposition, the lower most end 174 thereof bearingly contacts the bore 36of the housing 30a. It is apparent from the foregoing that the thirdvalve stem 128a is supported in the valve body 76a and the disc valvemember 102a by the housing 30a.

OPERATION OF FIGS. 3 AND 4 The valve assembly 10a will operatesubstantially like the valve assembly 10 shown in FIGS. 1 and 2. Thevalve unit 14a is assembled as a separate unit, and is adapted to beinserted axially into the housing unit 12a.

The salient differences between the valve assembly 10 and the valveassembly 10a include the manner in which the disc valve member 102a issupported in the valve body 300; the third valve stem 128a beingsupported by the housing 30, and thus not pinned in the disc valvemember 102a; the fact that a seating surface is not formed in the valvebody 76a, but rather a removable valve seat 156 is provided therein; andthat the disc valve member 102a is spherically shaped about a majorportion of the outer periphery 104a thereof.

As the disc valve member 102a, is rotated from the open to the closedposition, the only portions thereof which contact the valve body 76a arethe outer ends 168 and 172 of the raised portions 166 and 170,respectively. Therefore, the total contacting area between the discvalve member 102a and the valve body 76a is reduced as compared to thevalve assembly 10. This is particularly desirable when handling fluidscontaining foreign particles which might become trapped between the discvalve member and the seating surface, or in the handling of corrosivefluids.

It is apparent from the foregoing that the valve assembly 10a retainsall of the advantages of the valve assembly 10 with respect to theparticular construction of the second valve stem and the disc valvemember, and with respect to the inner periphery of the bore in thehousing being sized larger than the outer periphery of the valve body.

Changes may be made in the construction and arrangement of parts orelements of the various embodiments as disclosed herein withoutdeparting from the spirit and scope of the invention.

What is claimed is:

l. A valve assembly for controlling the flow of fluid between a pair ofaligned pipe flanges comprising:

a housing unit, including:

a housing having opposite end faces and a bore extending therethrough;

bolt means supporting the housing between the flanges;

a first valve stem having an upper and a lower end, journaled in thehousing; and

a valve unit, including:

a valve body extending lengthwise into the housing having opposite endfaces and a bore extending therethrough intersecting said opposite endfaces, the major portion of the outer periphery of said valve bodyhaving a diameter less than the diameter of the bore in the housmg;

means supporting the valve body in the housing;

a hollow substantially hemispherically shaped disc valve member havingan outer edge therearound, in the bore of the valve body for opening andclosing the valve assembly;

a second valve stem secured to the disc valve member having an upper anda lower end portion and being journaled in the valve body, said upperend being connected to the first valve stem for transmitting themovement of the first valve stem to the disc valve member;

a third valve stem having an upper and lower end, said third valve stembeing connected to the disc valve member and journaled in the valvebody; and

seat means disposed in the valve body sealingly engaging a portion ofthe disc valve member when the disc valve member is in the closedposition.

2. The valve assembly of claim 1 wherein the seat means includes anannular elastomeric seat ring disposed in the bore of the valve body,said seat ring having a seating and sealing surface formed on a portionthereof, said seating and sealing surface seatingly and sealinglyengaging a portion of the outer periphery of the disc valve member.

3. The valve assembly of claim 1 wherein the valve body is furtherdefined to include a spherically shaped seating surface formed in aportion of the bore thereof, said seating surface seatingly andslidingly contacting a portion of the outer periphery of the disc valvemember.

4. The valve assembly of claim 3 wherein the valve body is furtherdefined to include an annular groove formed in the seating surface; andan O-ring seal member disposed in said groove, said O-ring seal membersealingly engaging a portion of the exterior surface of the disc valvemember about an entire periphery thereof.

5 The valve assembly of claim 1 wherein the housing includes acounterbore adjacent one end thereof; and wherein the means supportingthe valve body in the housing includes a flange portion on one end ofthe valve body extending radially therefrom, said flange portionmatingly fitting in said counterbore, thereby positioning the valve bodyin the housing.

6. The valve assembly of claim 1 wherein the means supporting the valvebody in the housing includes a flange portion on the valve body havingan end face surface extending radially therefrom, said flange portioncooperating with said housing and one of said flanges to support andposition the valve body in the housing.

7. The valve assembly of claim 6 wherein said flange portion is sizedsuch that the end face surface thereof facing away from the valve bodyprotrudes beyond the adjacent end face of the housing when the valvebody is inserted in the housing.

8. The valve assembly of claim 7 wherein the length of the valve bodybetween the end face surface of the flange portion and the opposite endface of the valve body is less than the length of the housing betweenthe opposite ends thereof.

9. The valve assembly of claim 1, wherein the disc valve member isdefined further to include, an upper flange portion having an outerperiphery and an aperture extending therethrough, said upper flangebeing formed on the outer edge of the disc valve member and extendinggenerally axially therefrom when the disc valve member is in the closedposition, said aperture slidingly receiving the lower end portion of thesecond valve stem.

10. The valve assembly of claim 9 wherein the disc valve member isdefined further to include the lower flange portion havin an outerlperiphery and an aperture extending there ough, said ower flange beingformed on the outer edge of the disc valve member and extendinggenerally axially therefrom when the disc valve member is in the closedposition, said aperture slidingly receiving the upper portion of thethird valve stem.

11. The valve assembly of claim 10 wherein the lower end portion of thethird valve stem extends radially from the outer periphery of the valvebody and bearingly contacts the bore of the housing, said third valvestem being thereby supported in position by the housing.

1. A valve assembly for controlling the flow of fluid between a pair ofaligned pipe flanges comprising: a housing unit, including: a housinghaving opposite end faces and a bore extending therethrough; bolt meanssupporting the housing between the flanges; a first valve stem having anupper and a lower end, journaled in the housing; and a valve unit,including: a valve body extending lengthwise into the housing havingopposite end faces and a bore extending therethrough intersecting saidopposite end faces, the major portion of the outer periphery of saidvalve body having a diameter less than the diameter of the bore in thehousing; means supporting the valve body in the housing; a hollowsubstantially hemispherically shaped disc valve member having an outeredge therearound, in the bore of the valve body for opening and closingthe valve assembly; a second valve stem secured to the disc valve memberhaving an upper and a lower end portion and being journaled in the valvebody, said upper end being connected to the first valve stem fortransmitting the movement of the first valve stem to the disc valvemember; a third valve stem having an upper and lower end, said thirdvalve stem being connected to the disc valve member and journaled in thevalve body; and seat means disposed in the valve body sealingly engaginga portion of the disc valve member when the disc valve member is in theclosed position.
 2. The valve assembly of claim 1 wherein the seat meansincludes an annular elastomeric seat ring disposed in the bore of thevalve body, said seat ring having a seating and sealing surface formedon a portion thereof, said seating and sealing surface seatingly andsealingly engaging a portion of the outer periphery of the disc valvemember.
 3. The valve assembly of claim 1 wherein the valve body isfurther defIned to include a spherically shaped seating surface formedin a portion of the bore thereof, said seating surface seatingly andslidingly contacting a portion of the outer periphery of the disc valvemember.
 4. The valve assembly of claim 3 wherein the valve body isfurther defined to include an annular groove formed in the seatingsurface; and an O-ring seal member disposed in said groove, said O-ringseal member sealingly engaging a portion of the exterior surface of thedisc valve member about an entire periphery thereof.
 5. The valveassembly of claim 1 wherein the housing includes a counterbore adjacentone end thereof; and wherein the means supporting the valve body in thehousing includes a flange portion on one end of the valve body extendingradially therefrom, said flange portion matingly fitting in saidcounterbore, thereby positioning the valve body in the housing.
 6. Thevalve assembly of claim 1 wherein the means supporting the valve body inthe housing includes a flange portion on the valve body having an endface surface extending radially therefrom, said flange portioncooperating with said housing and one of said flanges to support andposition the valve body in the housing.
 7. The valve assembly of claim 6wherein said flange portion is sized such that the end face surfacethereof facing away from the valve body protrudes beyond the adjacentend face of the housing when the valve body is inserted in the housing.8. The valve assembly of claim 7 wherein the length of the valve bodybetween the end face surface of the flange portion and the opposite endface of the valve body is less than the length of the housing betweenthe opposite ends thereof.
 9. The valve assembly of claim 1, wherein thedisc valve member is defined further to include, an upper flange portionhaving an outer periphery and an aperture extending therethrough, saidupper flange being formed on the outer edge of the disc valve member andextending generally axially therefrom when the disc valve member is inthe closed position, said aperture slidingly receiving the lower endportion of the second valve stem.
 10. The valve assembly of claim 9wherein the disc valve member is defined further to include the lowerflange portion having an outer periphery and an aperture extendingtherethrough, said lower flange being formed on the outer edge of thedisc valve member and extending generally axially therefrom when thedisc valve member is in the closed position, said aperture slidinglyreceiving the upper portion of the third valve stem.
 11. The valveassembly of claim 10 wherein the lower end portion of the third valvestem extends radially from the outer periphery of the valve body andbearingly contacts the bore of the housing, said third valve stem beingthereby supported in position by the housing.